What Are the Stages of Brain Tumors?

Staging is the term oncologists use to define where cancer is located and how much it has spread. A staging system is used for most other types of cancer, but tumors of the brain are instead given grades. This is because most primary tumors of the brain do not typically spread beyond your central nervous system.

Northwestern Medicine oncologists use a grading system developed by the World Health Organization as one key factor to help them determine how to best treat brain tumors. A tumor's grade is determined by looking at cells from the tumor under a microscope.

Grade I: The least malignant and slowest growing, cells in a grade I tumor look like normal brain cells. Your physician may choose to remove a grade I tumor with surgery, if it can be done safely. Or your treatment may include medication and yearly MRI scans to monitor growth.

Grade II: This tumor has cells that appear less normal under a microscope and is considered malignant. A grade II tumor grows slowly, but has more of a chance to spread into nearby tissue or to recur. If removed, it may come back as a higher grade tumor.

Grade III: This tumor is malignant, grows quickly and is likely to spread into nearby tissue. When removed, it often comes back as a grade IV tumor.

Grade IV: This type of tumor is the most malignant, with cells that are very abnormal. It grows and spreads quickly into others areas of the brain. Surgery is unable to reach all of these areas without harming the brain, so other types of treatment are often needed.

For more information on the grades of tumors of the brain, please visit our Health Library.

Contact Us

For more information or to request an appointment at the Malnati Brain Tumor Institute of the Lurie Cancer Center at Northwestern Memorial Hospital, call 312.694.6037.

For more information or to request an appointment in the western suburbs, contact the Northwestern Medicine Regional Medical Group at 630.232.0610 (Geneva) or 630.352.5450 (Warrenville).

Related Resources

Lou and Jean Malnati Brain Tumor Institute at the Robert H. Lurie Comprehensive Cancer Center at Northwestern Memorial Hospital
Brain and Spine Tumor Center brochure: Learn about the Brain and Spine Tumor Center at Central DuPage Hospital and Delnor Hospital